Sea anchor or changeable drag

ABSTRACT

A device of the nature of a sea-anchor has a body tapered to the nose where it is attachable to a cable from a boat and formed with ports normally closed by spring-loaded closures but opened, by predetermined cable tension, to increase resistance to passage through water. Tail fins behind the body, and water passages through the body restrict rotation of the device. A chamber in the body when air-filled converts the device to a distress buoy, the tail fins uppermost to serve as a radar reflector, aerial for a distress transmitter in the body and carrier for a light.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

This invention relates to an improved sea-anchor or like device.

(2) Brief Description of the Prior Art

Sea-anchors or drag-anchors have long been known and made in a widevariety of forms, such a device being attached to a hawser paid out froma ship or boat to check the leeway of a drifting vessel or to prevent itfrom broaching-to.

SUMMARY OF THE PRESENT INVENTION

The general object of the present invention is to provide a device ofthis general character which may be used for the foregoing purposes andalso to apply more or less constant restraint to a vessel running beforea sea, and to serve as emergency steering means. A further objectachievable in preferred embodiments of the invention is to provide sucha device which may operate as an effective distress buoy with signalingmeans to assist and guide searchers.

With the foregoing and other objects in view the invention residesbroadly in a sea-anchor or like device including a body; attachmentmeans for attaching a hawser to the body; movable members on the body,and actuating means so connecting the attachment means to the movablemembers that when the application of predetermined tension through ahawser to the attachment means, the movable members are moved toincrease the resistance of the body to passage through water. Preferablythe body is hollow, with a number of ports therein, the movable membersbeing closures therefor, the attachment means being movablelongitudinally relative to the body, spring-loading means urging theclosure to closed position, the actuating means acting to move theclosures to open position against the action of the spring-loadingmeans. As a restraint against spinning of the body in the water,preferably the body has water flow through passages from its front toits rear, and behind its rear an assembly of fins. Other features of theinvention will become apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the invention is shown in the accompanyingdrawings, wherein:

FIG. 1 is a side elevational view of a device according to the inventionwith its port closure plates fully closed,

FIG. 2 is a longitudinal sectional view of the device shown in FIG. 1,

FIG. 3 is a front end view of the device,

FIG. 4 is a rear end view of the device,

FIG. 5 is a sectional view similar to FIG. 2, but showing the portclosure plates of the device fully opened,

FIG. 6 is a cross-sectional view of the device taken along line 6--6 inFIG. 5, and

FIG. 7 is a side elevational view of the device to reduced scale, in avertical rather than horizontal position, to serve as a distresssignalling device as well as a sea-anchor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The device shown in the drawings includes a body 10 and a nose cone 11.The body 10 comprises a front part 12 and a rear part 13, the nose cone11 when in normal retracted position as shown in FIGS. 1 and 2 forming,with the front part 12 of the body, a conical assembly increasing indiameter from front to rear, the rear part 13 of the body being offrusto-conical shape diminishing in diameter from front to rear. Thenose cone 11 is preferably of stainless steel, but the front and rearparts 12 and 13 of the body may be of a tough moulded plastics materialsecured coaxially together in any suitable manner.

The nose cone 11 is fixed on the front end of a shaft 14 which isclosely engaged in the axial bore of an internal boss 15 in the nosecone and secured by a dimetral locking bolt 16. The nose cone shaft 14enters the body 10 coaxially by way of a fore-end bush 17 passingthrough a central hole in the front of the body front part 12 andthreadedly engaged in the front part of an axial tube 18 through thebody 10, its rear end being engaged in a central hole in the back of therear part 13 of the body and secured by a locking plug 19 screwed intothe rear end of the axial tube and bearing on the back of the rear part13 of the body.

The axial tube 18 is formed, from its front, with four equally spacedlongitudinal radial slots 20. A nut 21 screwed onto the front part ofthe axial tube 18 bears against the front wall of the body front part12.

The rear end of the nose cone shaft 14 is fixed coaxially in a plunger21a having four radiating lugs 22 which are slidable in the slots 20. Ahelical compression spring 23 about the nose cone shaft 14 between thefore-end bush 17 and the plunger 21 urges the plunger to its rearmostposition, as shown in FIG. 2, the nose cone 11 then being against thefront of the body front part 12.

A middle plug 24 in the axial tube 18 defines the front end of a sealedtransmitter compartment 25 in the rear part of the tube 18.

Four longitudinal and parallel tubular flow-through water passages 26extend through the body 10, from elongated inlets at the coned frontpart 12 of the body to outlets in the rear wall of the body rear part13, the radial length of the outlets being diminished because of theconed formation of this rear part. For ease of manufacture, each of thetubular flow-through water passages 26 is in two sections, formedintegrally with the two parts 12 and 13 of the body and with spigot andsocket interfitment at 27.

Formed integrally with the rear part 13 of the body 10 is a coaxialcylindrical housing 28, spaced about the axial tube 14 so that anannular chamber 29 is formed between the two. Within this chamber thereis packed an annular air bladder 30, normally collapsedconcertina-fashion, but capable of being inflated with air introducedunder pressure by way of a nipple 31 at the back of the rear body part13.

Four equally spaced ports 32 of similar configuration are formed throughthe front part 12 of the body, each increasing in breadth from its frontto its rear terminating at the junction of the body's front and rearparts 12 and 13.

Each of the ports 32 is normally closed by a closure plate 33, its frontend hinged at 34 to the body front part 12. Within the body 10, draglinks 35 are connected between lugs 36 on the insides of the closureplates 33 and the lugs 22 on the plunger 21 so that, when the plunger 21is in its fully retracted position, the closure plates are held firmlyin their closed positions, and when the plunger 21 is advanced againstthe action of the compression spring 23, the drag links 35 move theclosure plates hingedly towards or to their fully opened positions, asshown in FIGS. 5 and 6.

A hawser 37 is made fast to a ring 38 through a diametral hole in thefront end of the nose cone 11. A number of water outlet openings 39 areformed through the frusto-conical wall of the rear part 13 of the body10.

A tail fin unit 40 has four fins or vanes 41 radiating from a centralhub 42 which is fixed coaxially to the rear plug 19. In certaincircumstances the tail fin unit may serve as an aerial for a radiodistress signal transmitter device 43 sealed within the compartment 25in the axial tube 18.

When the device is trailed from a vessel at the end of the hawser 37, itwill sink below the surface of the water and, because of the resistanceit offers, it will effect restraint on the vessel. The passage of waterthrough the flow-through water passages 26 and through their restrictedrear outlets past the tail fin unit 40 will ensure good stability of thedevice and prevent or greatly reduce any tendency of the device torotate about its axis.

If the vessel should be running before a sea, the tension on the hawserwill fluctuate, increasing considerably with each wave reaching thevessel, and with each such increase in tension the nose cone 11 and itsshaft 14 will be extended from the body 10 against the action of thecompression spring 23 so that the drag links 35 will cause the closureplates 33 to be moved to partly or fully opened positions. Theturbulence of the water resulting from the opening of the ports 32 andthe pressure of its influx to the rear part 13 of the device materiallyincreases the drag applied to the hawser beyond the resistance offeredwhen the ports are closed and the water through which the device isdrawn flows smoothly over it. With a subsequent reduction on the tensionapplied through the hawser, the ports 32 will be automatically closed,or partly so, by the closure plates 33, reducing the drag of the device.

The device will be found to be valuable not only for a vessel underpower which is running before a sea but also as a sea anchor for avessel without power; and it may be used also for emergency steering inthe event of loss of rudder, the hawser being paid out from either portor starboard to create a hinge point for turning the vessel. Withincreased propulsion, greater resistance is offered by the device andthe vessel's turning response will be faster than would be the case witha conventional sea anchor or drag anchor.

When the device is not being used in the manner described but is onboard a vessel which is in distress, the tail fin unit 40 may bedetached and lifted to a mast head by a halyard for use as a radarreflector to give a clear reading in response to a radar search.

If the vessel appears about to be lost and the crew are about to take toa life boat or raft, the bladder 30 may be inflated so that, as shown inFIG. 7, the device will float with the nose cone 11 down, a strobe light44 may be screwed into the tail fin unit 40 and put into operation, andthe radio distress signal transmitter device 43 may be actuated. A cable45 connected between the tail fin unit 40, for which purpose a hole isprovided in one of the vanes 41, and the hawser 37 will enable thedevice, floating upright, to serve not only as a distress buoy but alsoas a sea-anchor trailed from the life boat or raft by the hawser 37, thedistress signal transmitter, strobe light and radar reflector assistingsearchers to locate and rescue the crew.

I claim:
 1. A sea-anchor or like device including:a hollow body,attachment means, movable longitudinally in relation to the body forattaching a hawser to the body, a plurality of ports formed in the body,closures for the ports, spring-loading means urging the closures toclosed position, and actuating means so connecting the attachment meansto the closures that, upon the application of predetermined tensionthrough a hawser to the attachment means, the closures are moved to openposition against the action of the spring-loading means to increase theresistance of the body to passage through water.
 2. A sea-anchor or likedevice according to claim 1 wherein:the attachment means is on thefore-end of a shaft slidable in the body, and the actuating meansincludes links connecting the shaft to the closures.
 3. A sea-anchor orlike device according to claim 1 wherein:the body has a substantiallyconical front part tapering to the front and a substantiallyfrustoconical rear part tapering towards the rear, the ports are formedin substantially equally spaced arrangement in the body front part, eachtapering towards its front, and the closures are hinged at their frontsto the body front part for hinged movement into the body.
 4. Asea-anchor or like device according to claim 1 wherein:an assembly offins is mounted behind the rear of the body, and a plurality of waterflow-through passages are formed through the body from its front part toits rear.
 5. A sea-anchor or like device according to claim 4 wherein:achamber within the rear part of the body may, by the introduction ofair, be made a buoyancy chamber for bringing the body, in water, to anupright position, its assembly of fins uppermost, and the assembly offins serves as an aerial for a radio distress signal transmitter withinthe body.
 6. A sea-anchor or like device according to claim 5wherein:means are provided for mounting a signal light on the assemblyof fins. .Iadd.7. A sea anchor or like device comprising: a hollow bodyhaving front and rear parts, each of which has a forward and rear end,attachment means for attaching a line to the forward end of said frontpart for towing the body in a forward direction, said front part of saidbody having an outer surface which converges toward its forward end, andsaid rear part of said body having an outer surface which convergestowards its rear end, a plurality of ports formed in said body foradmission of water to the interior of the body, and at least one outletin said body for permitting escape of water from the interior of thebody..Iaddend. .Iadd.8. A sea anchor or like device as claimed in claim7 wherein said outer surface of said front part is generally conical,and said outer surface of said rear part is generallyfrustoconical..Iaddend. .Iadd.9. A sea anchor or like device as claimedin claim 8 wherein said ports are located adjacent to said front end ofsaid rear part of the body..Iaddend. .Iadd.10. A sea anchor or likedevice as claimed in claim 9 wherein said ports are equidistantly spacedabout the periphery of the body..Iaddend. .Iadd.11. A sea anchor or likedevice as claimed in claim 7, further including fins to resist rotationof the body..Iaddend. .Iadd.12. A sea anchor or like device as claimedin claim 7 wherein said at least one outlet is located in said rear partof the body..Iaddend. .Iadd.13. A sea anchor or like device comprising:ahollow body having front and rear parts, said each of which includes aforward end and a rear end, attachment means for attaching a line to theforward end of said front part for towing the body in a forwarddirection, said front part tapering radially outwardly from its frontend, said rear part tapering radially inwardly from its front end in adirection opposite to said forward direction, a plurality of ports foradmission of water to the interior of the body, and at least one outletin the body for permitting escape of water from the interior of thebody..Iaddend.